From 4f214b1ead0af7439921637645cb63f378516175 Mon Sep 17 00:00:00 2001
From: Hauke Mehrtens <hauke@hauke-m.de>
Date: Sat, 21 Jan 2012 18:48:38 +0100
Subject: [PATCH 33/34] b43: add workaround for b43 on pcie bus of bcm4716.

bcm4716 (which includes 4717 & 4718), plus 4706 on PCIe can reorder
transactions. As a fix, a read after write is performed on certain
places in the code. Older chips and the newer 5357 family don't require
this fix.
This code is based on the brcmsmac driver.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
 drivers/net/wireless/b43/b43.h        |   26 ++++++++++++++++++++++++++
 drivers/net/wireless/b43/bus.h        |   10 ++++++++++
 drivers/net/wireless/b43/phy_common.c |    6 ++++++
 drivers/net/wireless/b43/phy_n.c      |   10 +++++-----
 4 files changed, 47 insertions(+), 5 deletions(-)

--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -1047,6 +1047,32 @@ static inline bool b43_using_pio_transfe
 	return dev->__using_pio_transfers;
 }
 
+/*
+ * bcm4716 (which includes 4717 & 4718), plus 4706 on PCIe can reorder
+ * transactions. As a fix, a read after write is performed on certain places
+ * in the code. Older chips and the newer 5357 family don't require this fix.
+ */
+#ifdef CONFIG_BCM47XX_BCMA
+#include <asm/mach-bcm47xx/bcm47xx.h>
+static inline void b43_wflush16(struct b43_wldev *dev, u16 offset, u16 value)
+{
+	if (b43_bus_host_is_pci(dev->dev) &&
+	    bcm47xx_bus_type == BCM47XX_BUS_TYPE_BCMA &&
+	    (bcm47xx_bus.bcma.bus.chipinfo.id == 0x4716 ||
+	     bcm47xx_bus.bcma.bus.chipinfo.id == 0x5300)) {
+		b43_write16(dev, offset, value);
+		b43_read16(dev, offset);
+	} else {
+		b43_write16(dev, offset, value);
+	}
+}
+#else
+static inline void b43_wflush16(struct b43_wldev *dev, u16 offset, u16 value)
+{
+	b43_write16(dev, offset, value);
+}
+#endif
+
 /* Message printing */
 __printf(2, 3) void b43info(struct b43_wl *wl, const char *fmt, ...);
 __printf(2, 3) void b43err(struct b43_wl *wl, const char *fmt, ...);
--- a/drivers/net/wireless/b43/bus.h
+++ b/drivers/net/wireless/b43/bus.h
@@ -60,6 +60,16 @@ static inline bool b43_bus_host_is_sdio(
 	return (dev->bus_type == B43_BUS_SSB &&
 		dev->sdev->bus->bustype == SSB_BUSTYPE_SDIO);
 }
+static inline bool b43_bus_host_is_pci(struct b43_bus_dev *dev)
+{
+	if (dev->bus_type == B43_BUS_SSB)
+		return (dev->sdev->bus->bustype == SSB_BUSTYPE_PCI);
+#ifdef CONFIG_B43_BCMA
+	if (dev->bus_type == B43_BUS_BCMA)
+		return (dev->bdev->bus->hosttype == BCMA_HOSTTYPE_PCI);
+#endif
+	return false;
+}
 
 struct b43_bus_dev *b43_bus_dev_bcma_init(struct bcma_device *core);
 struct b43_bus_dev *b43_bus_dev_ssb_init(struct ssb_device *sdev);
--- a/drivers/net/wireless/b43/phy_common.c
+++ b/drivers/net/wireless/b43/phy_common.c
@@ -251,6 +251,12 @@ void b43_phy_write(struct b43_wldev *dev
 {
 	assert_mac_suspended(dev);
 	dev->phy.ops->phy_write(dev, reg, value);
+#ifdef CONFIG_BCM47XX
+	if (b43_bus_host_is_pci(dev->dev) && reg == 0x72) {
+		b43_read16(dev, B43_MMIO_PHY_VER);
+		return;
+	}
+#endif
 	if (++dev->phy.writes_counter == B43_MAX_WRITES_IN_ROW) {
 		b43_read16(dev, B43_MMIO_PHY_VER);
 		dev->phy.writes_counter = 0;
--- a/drivers/net/wireless/b43/phy_n.c
+++ b/drivers/net/wireless/b43/phy_n.c
@@ -4837,14 +4837,14 @@ static inline void check_phyreg(struct b
 static u16 b43_nphy_op_read(struct b43_wldev *dev, u16 reg)
 {
 	check_phyreg(dev, reg);
-	b43_write16(dev, B43_MMIO_PHY_CONTROL, reg);
+	b43_wflush16(dev, B43_MMIO_PHY_CONTROL, reg);
 	return b43_read16(dev, B43_MMIO_PHY_DATA);
 }
 
 static void b43_nphy_op_write(struct b43_wldev *dev, u16 reg, u16 value)
 {
 	check_phyreg(dev, reg);
-	b43_write16(dev, B43_MMIO_PHY_CONTROL, reg);
+	b43_wflush16(dev, B43_MMIO_PHY_CONTROL, reg);
 	b43_write16(dev, B43_MMIO_PHY_DATA, value);
 }
 
@@ -4852,7 +4852,7 @@ static void b43_nphy_op_maskset(struct b
 				 u16 set)
 {
 	check_phyreg(dev, reg);
-	b43_write16(dev, B43_MMIO_PHY_CONTROL, reg);
+	b43_wflush16(dev, B43_MMIO_PHY_CONTROL, reg);
 	b43_maskset16(dev, B43_MMIO_PHY_DATA, mask, set);
 }
 
@@ -4863,7 +4863,7 @@ static u16 b43_nphy_op_radio_read(struct
 	/* N-PHY needs 0x100 for read access */
 	reg |= 0x100;
 
-	b43_write16(dev, B43_MMIO_RADIO_CONTROL, reg);
+	b43_wflush16(dev, B43_MMIO_RADIO_CONTROL, reg);
 	return b43_read16(dev, B43_MMIO_RADIO_DATA_LOW);
 }
 
@@ -4872,7 +4872,7 @@ static void b43_nphy_op_radio_write(stru
 	/* Register 1 is a 32-bit register. */
 	B43_WARN_ON(reg == 1);
 
-	b43_write16(dev, B43_MMIO_RADIO_CONTROL, reg);
+	b43_wflush16(dev, B43_MMIO_RADIO_CONTROL, reg);
 	b43_write16(dev, B43_MMIO_RADIO_DATA_LOW, value);
 }
 
